A cemented carbide comprising a first hard phase composed of tungsten carbide particles and a binder phase including Co, the cemented carbide having a ratio Nt/Na of 0.9 or more, where, in any surface or any cross section of the cemented carbide, a region in which there is a distance X of 5 nm or less between surfaces respectively of tungsten carbide particles adjacent to each other, the surfaces facing each other along a length L of 100 nm or more, is referred to as a WC/WC interface, and Na represents a total number of WC/WC interfaces and Nt represents a number of WC/WC interfaces having distance X of 1 nm or more and 5 nm or less and having therein an atomic percentage of Co higher than an average value of atomic percentages of Co in the tungsten carbide particles.